Indapamide
thiazide diuretic · antihypertensive
Third-party optionBy the Layer Nutrition editorial team · How the atlas classifies the 664 molecules
What this medicine is for
Indapamide is a medicine in the 'thiazide diuretic (antihypertensive)' category. Diuretics help the kidneys eliminate water and salt, which lowers blood pressure and relieves oedema.
For Indapamide, in practice: Increases the elimination of water and salt by the kidneys and lowers blood pressure. It is most often a long-term treatment, taken at set times over long periods; its benefit is judged over time, not by how you feel on a given day.
Under which brands it is found
In France, about 28 reimbursable presentations containing Indapamide are recorded. It is found under several brand names and as generics.
- Arlunis
- Bipreterax
- Fludex
- Indapamide Arrow
- Indapamide Biogaran
- Indapamide Cristers Lp
- Indapamide Eg Lp
- Indapamide Krka Lp
- and other presentations
Original brand-name products and generics deliver the same active substance; the choice between them is made with your doctor or pharmacist.
On the plate: potassium and magnesium
On indapamide, the body eliminates more potassium and magnesium in the urine. Food is the first lever for rebuilding these two minerals, and the easiest to keep up day after day.
Potassium is found in abundance in fruit and vegetables: dried apricots, raisins, potato, spinach, broccoli, avocado, banana and orange. Beans, lentils, yoghurt and salmon also provide a good share. Magnesium comes mainly from almonds and cashews, pumpkin seeds, black and red beans, leafy green vegetables, brown rice, oats and dark chocolate of at least 70 percent.
Several of these foods provide both at once: spinach, beans and banana cover part of the potassium and magnesium in the same meal. By slipping them regularly onto your plate, you top up these stores in addition to your treatment, never in its place.
How indapamide works
Indapamide is a thiazide-like diuretic. It is not a true thiazide: it is a sulfonamide derivative built around an indole nucleus, known as an indoline. It acts on the kidney, at the cortical diluting segment, that is the distal convoluted tubule, where it inhibits sodium reabsorption. By slowing this reabsorption, it increases the urinary elimination of sodium and chloride, and therefore of salt and water.
At the doses used against hypertension, its action is not limited to this diuretic effect. Indapamide reduces the resistance of the small peripheral arteries and improves arterial compliance, that is the ability of the arteries to stretch. It acts with little or no effect on cardiac output, heart rate or heart rhythm. Blood pressure falls through these two combined pathways, renal and vascular.
Why indapamide is prescribed
Indapamide is indicated for the treatment of high blood pressure. It is prescribed on its own, when it is enough to bring blood pressure into the target range, or in combination with other antihypertensives when several mechanisms need to be combined. This is its main purpose, and the indication for which it is most used at low doses.
In the United States, the label also lists an indication for the salt and water retention of congestive heart failure, with a starting dose of 2.5 mg in the morning. In this setting, it is the diuretic effect that is sought, to help the body flush out the excess water and salt. The aim nevertheless remains primarily to lower blood pressure, and the reduction in pressure is obtained at low doses.
How to take it day to day
In hypertension, the starting dose is 1.25 mg as a single morning dose. It can be increased in four-week steps up to 5 mg per day, according to the blood pressure response. The extended-release form, Natrilix SR 1.5 mg, is taken as one tablet every 24 hours, preferably in the morning, swallowed whole with water and without chewing. Taking it in the morning avoids waking at night, since the medicine makes you pass more urine.
Regularity governs the whole benefit: one dose a day, at the same time, without skipping a day. The elimination half-life of the extended-release form is 14 to 24 hours, with an average of 18 hours, which allows 24-hour coverage with a single dose. It should not be stopped on your own initiative: high blood pressure is not felt, and pressure rises again with no warning sign as soon as it is stopped. Any change is decided with the doctor.
The effects to know, and how often they occur
The most frequent effect is a fall in blood potassium, hypokalaemia, classed as common, meaning between one patient in a hundred and one in ten. In trials conducted at 1.25 mg, 20 percent of patients had at least one potassium level below 3.4 mEq/L, and symptomatic hypokalaemia occurred in 2 percent. The fall depends on the dose: on average 0.28 mEq/L at 1.25 mg, 0.61 mEq/L at 5 mg and 0.76 mEq/L at 10 mg per day. It is the parameter most closely monitored on this treatment.
The other effects are distributed according to their frequency. Hyponatraemia and erectile dysfunction are uncommon, between one case in 1000 and one in 100; hypersensitivity reactions and maculopapular rashes are common; hypomagnesaemia and hypochloraemia are rare, and hypercalcaemia very rare. Blood glucose and blood uric acid may rise, at an undetermined frequency: uric acid increases on average by about 0.69 mg/100 mL at 1.25 mg, and a gout attack may be triggered in patients who are already hyperuricaemic. Severe hyponatraemia, accompanied by hypokalaemia, has been reported at the recommended doses.
Why potassium and magnesium fall
By blocking sodium reabsorption upstream, indapamide sends more sodium into the distal portions of the nephron, where it is partly exchanged for potassium: potassium then leaves more abundantly in the urine. Magnesium follows a similar logic, because thiazide-like diuretics increase its urinary excretion, which can lead to hypomagnesaemia. These are the two minerals whose stores are depleted on this treatment.
Calcium, by contrast, moves in the opposite direction: thiazides and related diuretics reduce its urinary excretion, which can cause a slight and transient rise in blood calcium. Sugar metabolism is also involved, since latent diabetes may be unmasked and the insulin needs of people with diabetes may change. For potassium and magnesium, food remains the simplest way to rebuild the stores, in addition to the treatment.
Interactions and laboratory monitoring
Monitoring rests first on electrolytes. Blood sodium is measured before treatment, then at regular intervals; the first potassium level should be obtained during the first week, and hypokalaemia below 3.4 mmol/L should be corrected. The US label recommends periodic measurement of serum electrolytes and periodic monitoring of uric acid during treatment.
In patients with diabetes, monitoring blood glucose is important, especially in the event of hypokalaemia, because the two affect each other. Indapamide is bound to plasma proteins to the extent of 71 to 79 percent, which matters when it is combined with other medicines. This laboratory monitoring allows the dose to be adjusted and imbalances to be caught early, before they become troublesome.
Sources
Related molecules
To explore in the « Heart and blood pressure » family and its neighbours.
See the whole « Heart and blood pressure » family · Back to the atlas
Supplements to consider
Beyond the plate, a single isolated nutrient can be worth discussing, to confirm with your doctor or pharmacist. Here is which one and in which form.
Magnesium
Magnesium is a mineral involved in many enzymatic reactions. Supplements differ mainly by their salt: organic forms such as bisglycinate and citrate are better tolerated digestively and better absorbed than oxide.
Preferred form bisglycinate or citrate rather than oxide
Potassium
Potassium is an electrolyte mineral. As a supplement, potassium citrate is a well-tolerated and bioavailable form; the elemental potassium content per capsule remains moderate owing to regulatory limits.
Preferred form potassium citrate
Frequently asked questions
What are the side effects of indapamide?
Public patient leaflets list, among others, drops in blood potassium, dizziness, fatigue, muscle cramps and, less commonly, skin reactions. The effects people experience vary from one person to another. Refer to the leaflet in your pack and report any symptom to your doctor or pharmacist.
What time of day should you take indapamide, and what if you miss a dose?
The leaflet advises taking it preferably in the morning because of the diuretic effect, to avoid having to get up at night. If you miss a dose, it recommends resuming your treatment as usual the next day without doubling up. Follow the dose set by your doctor and check these points with your pharmacist.
Is indapamide safe to take during pregnancy and breastfeeding?
Patient leaflets advise against indapamide during pregnancy and provide for an alternative treatment to be considered when a pregnancy is planned or confirmed. Breastfeeding is also not recommended. If this concerns you, discuss it with your doctor before making any decision.
Does indapamide have interactions with other medicines or alcohol?
Indapamide can interact with other medicines, in particular those that affect heart rhythm or potassium, and the leaflet mentions precautions regarding alcohol. The full list is in the leaflet. Tell your doctor or pharmacist about all the products you take, including over-the-counter ones.
Why are potassium and magnesium monitored while taking indapamide?
The summary of product characteristics states that indapamide increases the urinary excretion of sodium, and to a lesser extent that of potassium and magnesium. A first check of blood potassium is usually scheduled within the week following the start of treatment. It is your doctor who interprets these results and decides on any action.
On the nutrition side, what nutrient should you consider when taking indapamide?
Magnesium is the active most often mentioned: the summary of product characteristics notes that indapamide also increases, to a lesser extent, the urinary excretion of magnesium, and clinical work links low potassium that is hard to correct with magnesium that is itself low. In practice, a well-tolerated form such as magnesium bisglycinate, as a single active, is preferred. Potassium, for its part, is tracked with a blood test and managed with your doctor, never on a self-service basis.
Ces réponses portent sur le volet nutritionnel. Pour toute question sur votre médicament, la notice et votre médecin ou pharmacien font foi.